Alterations of glomerular filtration rate during cold exposure in progressive systemic sclerosis: measurement with technetium-99m DTPA.

We investigated the changes of the glomerular filtration rate (GFR) that occurred when the right hand was soaked in 7 degrees C water. The subjects were 5 patients with progressive systemic sclerosis who did not have clinical evidence of renal involvement. The clearance rate constant of 99mTc-DTPA, which is excreted by glomerular filtration, was measured with a cadmium telluride detector placed over the chest wall. In response to the cold exposure, the constant rose in 2 patients and remained unchanged in the remaining 3 patients. After termination of cold exposure, the constant fell in all 5 patients, suggesting renal Raynaud's phenomenon. These findings suggest that the renal vasculature in these patients has an abnormal response to cold exposure.